I am interested in using aluminum tubing for building a tubular chassis but most people say that aluminum does fatigue crack. But I was thinking that it has been done and aluminum can be used for a car chassis.
Audi uses aluminum for their monocoque chassis....
Is there anything I should know about this Audi chassis?
Isn't fatigue cracks also a problem with this Audi chassis since it's also made of aluminum....or perhaps also with the Acura NSX?
It does, but aluminum is more than one kind of thing. There are thousands of aluminum alloys. Some have worse fatigue problems than others. Some are easier to weld than others. Some are easier to machine than others.
Yes, you need to know what kind of aluminum alloy they use, first of all. Secondly, you need to know how the chassis was designed to avoid flexing and how they engineered welded joints to avoid flex points.
I don't know. But I'll say that fatigue cracking can be a major problem with aircraft, if you aren't careful. Aircraft designers work to distribute flexure so all the movement isn't in one place. And aircraft maintenance folks do regular inspections. Even so, sometimes things break like that
737 in Hawaii that had microcracking around rivet holes.--scott
Well said, Scott.
If you are not really an expert at design, welding, etc than one should perhaps not consider trying to develop a chassis from aluminum.
IIRC, the Norwegian aluminum producer (which name fails me at the moment) spent a lot of money and worked closely with the automobile industry to develop a high tech aluminum chassis. It was a work of art.
For most people, fabrication with large diameter thinwall tubing would be a lot easier and very competitive. This was described in a book by Costin, I believe, if he is lucky enough to find a copy. It is supposed to be the prime resource for high performance chassis development. (He is the Cos in Cosworth).
Yea, you can visit a F15 jockey while most of the early F15 fleet is grounded due to internal cracking of support structure....
Bob
Before you start this job make sure that you have a degree in mechanical engineering and are an expert in finite element modeling.
Of course it is taken for granted that you know how to use CAD software and that you have the money and resources to produce a predictable safe design.
HTH
Nah, FEM is for wimps who can't build real prototypes. Folks built big structures out of aluminum for decades without FEM. The ME degree sure wouldn't hurt, though.
The guys at Douglas sure did a nice job with the DC-3, with no CAD/CAM, no FEM, and no CNC machining. And aluminum alloys were a lot poorer controlled back then. Plenty of those aircraft are still flying with no sign of fatigue failures. Of course, they had a LOT of guys with ME degrees on staff.
--scott
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.